testing a/c compressor?

[Touchdown038]

Ok here we go... I noticed when I bought my 240 that there was no belt on the a/c compressor. I thought "ok, well I'm not gonna need a/c in Washington anyways" but then I got a little curious as to why it wasn't on there. Most likely it stopped working for the previous owner and he took the belt off himself, however I would have no way to confirm that. So, is there any way to test a compressor, preferably off-car, to see if it is operating correctly?

[blackbeauty240]

keep it on the car. if it has r12 in the system its a federal crime unless you have a license. the most common reason to take the belt off is that when the compressor runs low or out of oil it tears the compressor up and locks up the pulley. oil in the a/c is like oil in your engine it acts as a lubricant and without it you might as well kiss the engine good bye. just see if you can turn the pulley by hand if not then leave the belt off until you get a new compressor. if you can turn it put a belt on it. it it still doesnt work press the shrader valve on the high side of the compressor to see if you have any oil or refrigerant in it. if so and the compressor is turning on you should have a/c unless you have an internal blockage.

[Touchdown038]

I tried turning it by hand, and it would turn, but it had a little bit of resistance/grinding in it.... bad sign? I also checked the level of freon and oil and it didn't have any in it.

[blackbeauty240]

if you can turn it by hand then its not locked up. but from what your telling me i think you best move is to put a belt on it and if you dont hear any unusual noises when you turn the a/c on and still dont have cold air take it to a shop and get them to find out why it wont work. also r12 is highly expensive (I think the average price is about 60 bucks for a 12oz can most cars average 24oz) so if they find the leak and fix it ask about getting an r134 conversion. r134 runs about 8 bucks for 12oz compared to 60 for r12 and is not illegal to mess with.

[blackbeauty240]

oh yeah and the grinding noise might be a bad a/c clutch.